need more smoothness

Gmood has hit the nail on the head. Metal dome tweeters have a natural resonance about 20KHz that is audible and comes through just as you described. It is actually very simple to prove without using sophisticated test equipment. If you drop the metal dome of a tweeter on the floor you can hear it hit. Do the same with the silk dome and you cannot. There is on-going reseach in Finland at the University of Jyvaskyla's Department of Biology and Physics examining brain wave activity and sound.

The research has two aims, first to see if high frequency sounds above the human hearing influence the quality of music subjectively, and secondly, can this be observed and measured in brain wave activity and recorded by EEG, electroencephalography. The purpose is to scientifically study whether ultra-tweeters make a difference in the quality of the music.

Measurements of objective, subjective and physiological reactions are being recorded in different sound environments, including high-frequency sounds above 22 kHz. Another physiological measure is the heart rate variability, which is the time between two consecutive heartbeats. The heart rate variability is a delicate quantity that indicates a person’s stress state. (The Finns are big on healthcare research that focus on quality of life, heart rate and stress.)

The subjective evaluation entails test subjects completing a questionnaire regarding the sound quality of the different environments. These are then compared to their EEGs.

The baseline results prove the hypothesis, as well as show that humans subconsciously prefer the sound of wide-bandwidth music.


Sorry for the long response, but I have been on the fringe of this research, which is both cool and frustrating in that I am constantly second guessing my own system.

I would agree with the felting the tweeter advice above, but would also attack the problem (if you haven't already) with some very inexpensive power items. Cryoed Hubbell 5262 or 5362 outlets or Porter Ports, Quantum Electoclear Filter (approximately $40). For $100-$150, your system will be dramatically changed for the better by these items.

I agree that silk's are far less hostile than metal tweeters. However, the crossover slope shouldn't make a bit of difference in the presentation of the tweeter. The crossover has everything to do with the integration of tweeter and the mid/bass driver. The tonality of the tweeter is inherent in it's design and materials and how loud it is in comparison to the loudness of that mid/bass driver (talking about relative efficiency here).

Enjoy,
Bob

Once upon a time my rig suffered from tonal hardness (aka distortion) of upper register piano, soprano sax, flute and, as you mentioned, violin. Turns out it was the preamp. Switching from a Forte 44 to a Threshold Fet ten solved the problem across the board. So maybe your speakers are not to blame. Painlessly conveying the tough tones may be a job for finer, less distorting electronics.

Very interesting stuff Cellorover! In my limited experience, I always found that I preferred speakers which turned out to have silk/fabric tweeters. Though that is not to say that metal dome tweeters cannot be smooth, for example the nautilus line with good (smooth) amps.
As for the Finns and their research: do you think we could get them to do the same research with tubes vs ss!